/**
 *    Copyright (C) 2018-present MongoDB, Inc.
 *
 *    This program is free software: you can redistribute it and/or modify
 *    it under the terms of the Server Side Public License, version 1,
 *    as published by MongoDB, Inc.
 *
 *    This program is distributed in the hope that it will be useful,
 *    but WITHOUT ANY WARRANTY; without even the implied warranty of
 *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *    Server Side Public License for more details.
 *
 *    You should have received a copy of the Server Side Public License
 *    along with this program. If not, see
 *    <http://www.mongodb.com/licensing/server-side-public-license>.
 *
 *    As a special exception, the copyright holders give permission to link the
 *    code of portions of this program with the OpenSSL library under certain
 *    conditions as described in each individual source file and distribute
 *    linked combinations including the program with the OpenSSL library. You
 *    must comply with the Server Side Public License in all respects for
 *    all of the code used other than as permitted herein. If you modify file(s)
 *    with this exception, you may extend this exception to your version of the
 *    file(s), but you are not obligated to do so. If you do not wish to do so,
 *    delete this exception statement from your version. If you delete this
 *    exception statement from all source files in the program, then also delete
 *    it in the license file.
 */

#pragma once
#include "mongo/base/string_data.h"
#include "mongo/bson/bsonobj.h"
#include "mongo/bson/bsontypes.h"
#include "mongo/db/repl/idempotency_scalar_generator.h"
#include "mongo/util/modules.h"

#include <cstddef>
#include <set>
#include <vector>

namespace mongo {

class BSONArrayBuilder;
class StringData;

struct DocumentStructureEnumeratorConfig {
    DocumentStructureEnumeratorConfig(std::set<StringData> fields_,
                                      std::size_t depth_,
                                      std::size_t length_,
                                      bool skipSubDocs_ = false,
                                      bool skipSubArrs_ = false);

    std::set<StringData> fields = {};
    std::size_t depth = 0;
    std::size_t length = 0;
    const bool skipSubDocs = false;
    const bool skipSubArrs = false;
};

class DocumentStructureEnumerator {
public:
    using iterator = std::vector<BSONObj>::const_iterator;

    DocumentStructureEnumerator(DocumentStructureEnumeratorConfig config,
                                const ScalarGenerator* scalarGenerator);

    iterator begin() const;

    iterator end() const;

    std::vector<BSONObj> getDocs() const;

    std::vector<BSONObj> enumerateDocs() const;

    std::vector<BSONArray> enumerateArrs() const;

private:
    static BSONArrayBuilder _getArrayBuilderFromArr(BSONArray arr);

    static void _enumerateFixedLenArrs(const DocumentStructureEnumeratorConfig& config,
                                       const ScalarGenerator* scalarGenerator,
                                       BSONArray arr,
                                       std::vector<BSONArray>* arrs);

    static void _enumerateDocs(const DocumentStructureEnumeratorConfig& config,
                               const ScalarGenerator* scalarGenerator,
                               BSONObj doc,
                               std::vector<BSONObj>* docs);

    static std::vector<BSONArray> _enumerateArrs(const DocumentStructureEnumeratorConfig& config,
                                                 const ScalarGenerator* scalarGenerator);


    const DocumentStructureEnumeratorConfig _config;
    const ScalarGenerator* _scalarGenerator;
    std::vector<BSONObj> _docs;
};

}  // namespace mongo
